This application is based on an incorporates herein by reference Japanese Patent Application No. 2000-343646 filed on Nov. 10, 2000.
1. Field of the Invention
The present invention generally relates to a method for controlling a vehicular generator, an external controller and a vehicular power generation controlling device for controlling a power-generating state of a vehicular generator mounted on a vehicle, a truck or the like.
2. Description of Related Art
In general, a vehicular generator supplies power to a battery while the vehicle engine is running. Additionally, the generator provides power for engine ignition, lighting, and other various electrical components, while a generator controller is connected thereto in order to maintain a constant output voltage, even under varying load conditions. In recent years, driving torque of vehicular generators have increased as vehicular electrical loads have increased. If the driving torque of a vehicular generator grows excessively large while an engine is at idle speed, the engine speed becomes unstable. Therefore, a technique is known to avoid such a situation by controlling a power generation condition of the vehicular generator by a generator controller.
For example, in JP-A No. 7-194023, there is disclosed a generator controller that adjusts an output voltage of a vehicular generator to any value based on a duty ratio of a signal transmitted from an external control unit. When a duty signal corresponding to an adjusted voltage is transmitted through a communication line from the external controller unit, a converter within the generator controller converts the duty ratio of the signal to a voltage level so as to control an output voltage of the vehicular generator corresponding to the voltage level thereof.
Moreover, in JP-A No. 8-98430, there is disclosed a generator controller that suppresses power generation of a vehicular generator during a predetermined period when a state of an external control signal is switched.
In the above-described generator controller disclosed in JP-A NO. 7-194023, a duty ratio is converted to a voltage level so that an output voltage of a vehicular generator is controlled corresponding to the voltage level. However, a variable range of the output voltage by the duty ratio is limited, and therefore, if it is left as it is, electrical power cannot be supplied during a high voltage load. Moreover, because a duty voltage converter has undesirable conversion accuracy, there is a problem that it is not possible to conduct a new duty setting.
Moreover, in the above-described power generating controlling device disclosed in JP-A No. 8-98430, in a case where a signal line connected with an external control unit is shorted out, there is a problem related to the possibility of an overcharged battery because the adjusted voltage transitions to a high level.
Additionally, in the external controller, if electrical power generation is set to be switched externally by using a special-purpose signal line in addition to a conventional signal line for a battery charge control, it leads to an addition of a harness and an extensive change of the external controller. Therefore, a substantial increase in cost may result.
Furthermore, in the above-described generator controller disclosed in JP-A No. 7-194023, in order to mutually convert between a duty ratio and a voltage level, a plurality of converters are necessary. Therefore, the problem of a particularly complicated circuit structure exists.
The present invention is created in view of these aspects, and its object is to provide compatibility with a conventional one, and transfer new information. Moreover, another object of the present invention is that by employing a signal condition that is conventionally unused, without changing the hardware of an external controller, a control value is set corresponding to a vehicle condition by updating software. Furthermore, another object of the present invention is to provide a simple structure without using such a complicated conversion circuit for sending a command value.
In order to solve the above-described problem, a controlling method of a vehicular generator of the present invention, in a case where a power generation state of the vehicular generator is controlled by transmitting a setting signal to a vehicular power generation controller from an external controller, on the external controller side, a command of a first controlling value is allocated to a steady state of the setting signal. Additionally, a command of a second controlling value is allocated to a change state of the setting signal, and on a vehicular power generation controlling device side, during a predetermined period after detecting the change state of the setting signal, the second controlling value being different from the first controlling value corresponding to the steady state is set as an output controlling value of the vehicular generator.
The external controller of the present invention controls a power generation state of a vehicular generator by transmitting a steady state of a setting signal expressing a command of a first controlling value and a change state of the setting signal expressing a command of a second controlling value for changing the first controlling value for a predetermined time.
A vehicular power generation controlling device of the present invention includes an external signal identifying means for identifying a steady state and a change state of a setting signal transmitted from an external controller, and a controlling value setting means for setting a second setting value different from a first controlling value corresponding to the steady state during a predetermined time after a change state of the setting signal is detected by the external signal identifying means.
A vehicular power generation controlling device of the present invention includes an external signal identifying circuit for identifying a steady state and a change state of a setting signal transmitted from an external controlled, and an adjustment voltage controlling circuit for setting a second controlling value as an adjustment voltage of a vehicular generator, the second controlling value being different from a first controlling value corresponding to the steady state, during a predetermined time after a change state of the setting signal is detected by the external signal identifying circuit, and controls a power generation state of the vehicular controller by using the first controlling value and the second controlling value set by the adjustment voltage controlling circuit.
When a state of the setting signal is change, the first controlling value used so far is change to a second controlling value. Because a change of a control value can be performed without using a converter of an undesirable conversion accuracy, it becomes possible to transfer new information, that has been impossible when using the converter. Moreover, on an information transmitting side, a timing of a state change of the setting signal is only controlled, and thus, hardware does not have to be changed, and it can be dealt with by simply updating software, thereby suppressing a significant increase of the cost. Moreover, the setting signal itself is the same as what is used in the conventional vehicular power generation controlling device, thus enabling to give compatibility with the conventional device.
The power generation state of the vehicular generator is controlled by using the first controlling value and the second controlling value, both being set by the adjustment voltage controlling circuit, and when a state of the setting signal changes, the adjustment voltage is change by using a second controlling value which is different from a first controlling value used up until then, and thus, it is, possible to shorten a response time for changing the adjustment voltage. Moreover, it is unnecessary to include a converter for converting a duty ratio to a voltage, and thus, it is possible to simplify the circuit structure. Therefore, deterioration of adjustment accuracy due to the conversion does not occur.
Moreover, the above-described external signal identifying circuit preferably includes a voltage comparing means for detecting the setting signal input to a terminal for receiving an external signal by comparing a predetermined reference value and a voltage level of the terminal, and a changing state detection means for detecting a change state of the setting signal detected by the voltage comparing means. By comparing the voltage level of the receiving terminal with the reference value, it becomes possible to easily detect whether or not there is a setting signal. By examining a change state of the detected setting signal, a steady state and a change state can be identified easily.
Moreover, the above-described adjustment voltage controlling circuit desirably has a timer means for starting measuring a set period when the change state is detected by the external signal identifying circuit, and sets the second controlling value as the adjustment voltage until a measuring operation by the timer means is finished. By using the timer means, it is possible to arbitrary set a time for using the second controlling value as the adjustment voltage.
The first controlling value preferably corresponds to a power generation state under a steady state of the vehicular generator. Under the steady state where a change state is not detected, the adjustment voltage is set based on the first controlling value corresponding to the power generation state under the steady state, and therefore, it is possible to prevent a battery from excessively being charged due to the adjustment voltage becoming too high when a signal line transmitting and receiving the setting signal is opened or shorted out.
The second controlling value preferably corresponds to a power generation suspension state of the vehicular generator. Or the second controlling value corresponds to a forced power generation state of the vehicular generator. By bringing to a sate of power generation to suspension or full power generation, the power generation state of the vehicular generator can be controlled easily.
The above-described setting signal has a plurality of the steady state of different voltage levels, and the adjustment voltage controlling circuit preferably sets a plurality of the first controlling value corresponding to each of the plurality of the steady state. Because a plurality of the first controlling values can be selectively set, it becomes possible to control the power generation corresponding to a sate and the like of the vehicle.
The above-described external signal identifying circuit preferably distinguishes, when identifying the change state, a first change state corresponding to rising of the setting signal and a second change state corresponding to a falling thereof, and the adjustment voltage controlling circuit sets the second controlling value corresponding to the first change state different to a different value from the second controlling value corresponding to the second change state. Because it is possible to set a different adjustment voltage by using rising and falling of the signal, it is possible to control power generation corresponding to a state and the like of the vehicle.
In particular, it is desirable that one of the second controlling value corresponding to the first change state and the second controlling value corresponding to the second change state corresponds to a power generation suspension state of the vehicular generator while the other corresponds to a force power generation state of the vehicular generator. By repeating a forced power generation state and a power generation suspension state, it becomes possible to externally control the power generation state by the duty ratio. Thereby, it is possible to control the adjustment voltage over a wide range by the external controller.
Moreover, it is desirable that the above-described setting signal has a predetermined duty ratio, one of the second controlling value corresponding to the first change state and the second controlling value corresponding to the second change state corresponds to a power generation suspension state of the vehicular generator while the other corresponds to a force power generation state of the vehicular generator, and the first controlling value corresponding to the steady state is set to a value corresponding to the duty ratio. When using the setting signal having the duty ratio, it is possible to set the adjustment voltage corresponding to the forced power generation state or the power generation suspension state separately from a control of the adjustment voltage corresponding to the duty ratio, thus enabling to control the adjustment voltage over a wide range by the external controller.
Furthermore, it is desirable that the above-described adjustment voltage controlling circuit sets, when in the steady state where the change state is not detected by the external signal identifying circuit, the first controlling value as an adjustment voltage, the first controlling value having a voltage value being continuously changeable by corresponding to a voltage level of the setting signal. It is possible to change the adjustment voltage continuously corresponding to the voltage level of the setting signal. Moreover, by changing a state of the setting signal, it becomes possible to set an adjustment voltage using a second controlling value which is totally different, thus, enabling to use the adjustment voltage depending on a state or the like of the vehicle.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.